Editing Ketone (section)

==Synthesis==<!-- This section is linked from [[Organic reaction]] -->
Many methods exist for the preparation of ketones in industrial scale and academic laboratories. Ketones are also produced in various ways by organisms; see the section on biochemistry below.

In industry, the most important method probably involves [[oxidation]] of [[hydrocarbons]], often with air. For example, a billion kilograms of [[cyclohexanone]] are produced annually by aerobic oxidation of [[cyclohexane]]. Acetone is prepared by [[cumene process|air-oxidation of cumene]].

For specialized or small scale [[organic synthesis|organic synthetic]] applications, ketones are often prepared by [[Alcohol oxidation#Oxidation to ketones|oxidation of secondary alcohols]]:
:{{chem2|R2CH(OH) + "O" → R2C\dO + H2O}}
Typical strong [[organic oxidation|oxidant]]s (source of "O" in the above reaction) include [[potassium permanganate]] or a [[chromium|Cr(VI)]] compound. Milder conditions make use of the [[Dess–Martin periodinane]] or the [[Swern oxidation|Moffatt–Swern]] methods.

Many other methods have been developed, examples include:<ref name=March>{{March6th}}</ref>
* By [[geminal halide hydrolysis]].<ref>{{cite journal|last1=Marvel|first1=C. S.|last2=Sperry|first2=W. M.|title=Benzophenone|journal=Organic Syntheses|date=1928|volume=8|page=26|doi=10.15227/orgsyn.008.0026}}</ref>
* By [[hydration reaction|hydration]] of [[alkyne]]s.<ref name=Vogel>{{cite book|last1=Furniss |first1=Brian |last2=Hannaford |first2=Antony |last3=Smith |first3=Peter |last4=Tatchell |first4=Austin |title=Vogel's Textbook of Practical Organic Chemistry|year=1996|publisher=Longman Science & Technical|location=London|edition=5th|isbn=9780582462366|pages=612–623, 976–977, 982–983|url=https://archive.org/details/TextbookOfPracticalOrganicChemistry5thEd}}</ref> Such processes occur via [[enol]]s and require the presence of an acid and [[mercury(II) sulfate]] ({{chem2|HgSO4}}). Subsequent enol–keto tautomerization gives a ketone. This reaction always produces a ketone, even with a terminal alkyne, the only exception being the hydration of [[acetylene]], which produces [[acetaldehyde]].
* From [[Weinreb ketone synthesis|Weinreb amides]] using stoichiometric organometallic reagents.
* [[Aromatic|Aryl]] ketones can be prepared in the [[Friedel–Crafts acylation]],<ref name="Friedel">{{cite journal|last1=Allen|first1=C. F. H.|last2=Barker|first2=W. E.|title=Desoxybenzoin|journal=Organic Syntheses|date=1932|volume=12|page=16|doi=10.15227/orgsyn.012.0016}}</ref> the related [[Houben–Hoesch reaction]],<ref>{{cite journal|last1=Gulati|first1=K. C.|last2=Seth|first2=S.R.|last3=Venkataraman|first3=K.|title=Phloroacetophenone|journal=Organic Syntheses|date=1935|volume=15|page=70|doi=10.15227/orgsyn.015.0070}}</ref> and the [[Fries rearrangement]].<ref name=Vogel />
* [[Ozonolysis]], and related dihydroxylation/oxidative sequences, cleave [[alkene]]s to give aldehydes or ketones, depending on alkene substitution pattern.<ref>{{cite journal|last1=Tietze|first1=Lutz F.|last2=Bratz|first2=Matthias|title=Dialkyl Mesoxalates by Ozonolysis of Dialkyl Benzalmalonates: Dimethyl Mesoxalate|journal=Organic Syntheses|date=1993|volume=71|page=214|doi=10.15227/orgsyn.071.0214}}</ref>
* From [[peroxides]] ([[Kornblum–DeLaMare rearrangement]]).
* Cyclization of [[dicarboxylic acid]]s ([[Ruzicka cyclization]])
* [[Hydrolysis]] of salts of secondary [[nitro compound]]s ( [[Nef reaction]]<ref>{{cite journal|last1=Heinzelman|first1=R. V.|title=o-Methoxyphenylacetone|journal=Organic Syntheses|date=1955|volume=35|page=74|doi=10.15227/orgsyn.035.0074}}</ref>)
* Alkylation of thioester with [[organozinc compound]]s ([[Fukuyama coupling]]).
* Alkylation of [[acid chloride]] with [[organocadmium compound]]s or [[organocopper compound]]s.
* The [[Dakin–West reaction]] provides an efficient method for preparation of certain methyl ketones from carboxylic acids.<ref>{{cite journal|last1=Wiley|first1=Richard H.|last2=Borum|first2=O. H.|title=3-Acetamido-2-butanone|journal=Organic Syntheses|date=1953|volume=33|page=1|doi=10.15227/orgsyn.033.0001}}</ref>
* Ketones can be prepared by the reaction of [[Grignard reagents]] with [[nitrile]]s, followed by hydrolysis.<ref>{{cite journal|last1=Moffett|first1=R. B.|last2=Shriner|first2=R. L.|title=ω-Methoxyacetophenone|journal=Organic Syntheses|date=1941|volume=21|page=79|doi=10.15227/orgsyn.021.0079}}</ref>
* By [[decarboxylation]] of [[carboxylic anhydride]].
* Ketones can be prepared from haloketones in [[reductive dehalogenation of halo ketones]].
* In [[ketonic decarboxylation]] symmetrical ketones are prepared from carboxylic acids.<ref name=Vogel /><ref>{{cite journal|last1=Thorpe|first1=J. F.|last2=Kon|first2=G. A. R.|title=Cyclopentanone|journal=Organic Syntheses|date=1925|volume=5|page=37|doi=10.15227/orgsyn.005.0037}}</ref>
* [[Hydrolysis]] of [[Saturated and unsaturated compounds|unsaturated]] [[Secondary (chemistry)|secondary]] amides,<ref>{{cite journal|last1=Herbst|first1=R. M.|last2=Shemin|first2=D.|title=Phenylpyruvic acid|journal=Organic Syntheses|date=1939|volume=19|page=77|doi=10.15227/orgsyn.019.0077}}</ref> [[Alpha and beta carbon|β]]-[[Keto acid]] esters,<ref name=Vogel /> or β-[[diketone]]s (the [[acetoacetic ester synthesis]]).  
* [[Pinacol rearrangement|Acid-catalysed rearrangement]] of [[Diol#Vicinal diols|1,2-diols]],<ref name=Vogel /> or [[Criegee oxidation]] of the same.